what IS BACTERIUM?

Answer 1

Bacteria (singular: bacterium) are microscopic, unicellular organisms. They are often coccus- (spherical) or rod-shaped and 0.5-5 µm in the longest dimension, although the wide diversity of bacterial diversity can display a huge variety of morphologies. The study of bacteria is known as bacteriology, a branch of microbiology.

Bacteria are ubiquitous in the environment, living in every possible habitat on the planet. There are typically ten billion bacterial cells in a gram of soil, and one hundred thousand bacterial cells in a millilitre of sea water. Bacteria play an important role in the cycling of nutrients in the environment, and many important steps in the nutrient cycle are catalysed exclusively by bacteria, such as the fixation of nitrogen from the atmosphere.

There are more bacterial cells on each of our bodies than there are our cells of our own and bacteria are a natural component of the human body, particularly on the skin and in the mouth and intestinal tract. Bacteria are important to human health, as they are the causative agent of many infectious diseases, including cholera and tuberculosis. Historically, bacteria have been responsible for such diseases as bubonic plague and leprosy, but after the discovery of antibiotics many bacterial diseases are able to be controlled.

Bacteria are also important to numerous industrial processes, such as wastewater treatment and more recently the industrial production of antibiotics and other chemicals.

The term "bacteria" has traditionally been generally applied to all microscopic, single-celled prokaryotes. Although this term remains in everyday use, the scientific nomenclature changed after the discovery that prokaryotic life actually consists of two very different lines of evolution (see three-domain system). Originally called Eubacteria and Archaebacteria, these evolutionary domains are now called Bacteria and Archaea.

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Answer 2

A bacterium is microscopic life form: a single-celled, often parasitic microorganism without distinct nuclei or organized cell structures. Various species are responsible for decay, fermentation, nitrogen fixation, and many plant and animal diseases.

Answer 3

bacterium - single celled, prokaryotic microorganism

Answer 4

bacterium is the singular. bacteria is the plural.

Answer 5

http://en.wikipedia.org/wiki/Bacterium

Answer 6

www.dictonary.com it gives definitions!!! try it!!